在无铅环境中的热风整平

当电子工业走向无铅焊接的时候,热风焊料整平仍然是继续可焊性保护的优选方法。     

Low-cycle fatigue properties of eutectic solders at high temperatures

This paper details the deformation mechanism and low‐cycle fatigue life of eutectic solder alloys at high temperature (around 0.8T_m). Grain boundary sliding generally nucleates a wedge‐type cavity that reduces the low‐cycle fatigue life of metals. In this study, grain boundary sliding has promoted intergranular failure contributing to the reduction in fatigue life of Sn–Ag–Cu alloy. However, grain boundary sliding has exerted no deleterious effects on fatigue resistance of eutectic Pb–Sn and Bi–Sn alloys. The phase boundary sliding with very fine microstructure induces exceptional ductility in these alloys leading to superior low‐cycle fatigue endurance for theses eutectic Pb–Sn and Bi–Sn alloys.     

Income, Time Effects and Direct Preferences in a Multimodal Choice Context: Application of Mixed RP/SP Models with Non-Linear Utilities

Transport problems typically involve at least two types of constraints, on income and on time. Therefore, the indirect utility function depends either on the income available after having subtracted the cost of the discrete alternative and on the free time left after having worked and travelled by each competing option. In the typical linear-in-the-attributes and in-the-parameters specification, that represents the first grade approximation of the indirect utility function, the effect of income and time constraints cancel out and only the cost and time of the alternatives matter in the comparison between them. From a microeconomic point of view this is equivalent to assume that income and time effects could be disregarded; which is not always the case. To account for these effects the utility function should include second order attributes; however, in non-linear utility functions it may not be easy to distinguish among several effects that could be relevant: direct preferences for good and leisure, and simple interactions between attributes other than income and time effects. This paper analyses these effects from a theoretical point of view focusing on the possible confounding problem in detecting income and time effects. We use a dataset collected for a modal choice context and containing both revealed and stated preference data, and estimate several NL models examining the effect of the different second-order terms on detecting income and time effects. We compared specifications including square cost and time attributes, interactions between time and cost, cost divided by the income available to be spent on free time, and time multiplied by free time. Our results confirm the strong effect of direct preferences for goods and leisure time on choice, and the potential confounding effect between quadratic attributes and other non-linear omitted terms. Finally, we also found that care should be taken in highlighting income and time effects using mixed data sources, since confounding effects can occur when non-linearities are accounted for in both data sets.     

二元复合驱阶段见效特征

针对孤东油田油藏条件，通过室内试验研究，确定了以胜利石油磺酸盐为活性剂主剂和聚合物的二元复合驱油体系，通过两者之间的协同效应，增加水驱波及体积和洗油效率。该体系在孤东油田七区西馆上54—61层进行试验，取得了较好的阶段性降水增油效果。本文分析了复合驱见效特征和影响见效因素，为下步跟踪分析调整具有指导意义。     

拟声波构建技术在砂泥岩薄互层储层预测中的应用

拟声波构建技术依据对储层敏感的非声波地球物理测井信息构建具有声波量纲的新曲线，进而形成拟声波曲线。由于该声波曲线既能反映地层速度和波阻抗的变化，又能反映地层岩性的细微差别，可以较好地解决薄互层储层定量预测中的岩性识别、薄层分辨等难题。针对歧口凹陷南大港地区地层实测声波时差曲线对砂、泥岩的岩性反映不明显，无法进行储层反演预测的问题，采用了拟声波构建技术。将对储层岩性敏感性好的自然电位曲线转换成拟声波曲线，以此为约束条件实现了储层预测的目的，取得了较好的应用效果。     

Complementary Effects of Carbamylated and Citrullinated LL37 in Autoimmunity and Inflammation in Systemic Lupus Erythematosus

LL37 acts as T-cell/B-cell autoantigen in Systemic lupus erythematosus (SLE) and psoriatic disease. Moreover, when bound to “self” nucleic acids, LL37 acts as “danger signal,” leading to type I interferon (IFN-I)/pro-inflammatory factors production. T-cell epitopes derived from citrullinated-LL37 act as better antigens than unmodified LL37 epitopes in SLE, at least in selected HLA-backgrounds, included the SLE-associated HLA-DRB1*1501/HLA-DRB5*0101 backgrounds. Remarkably, while “fully-citrullinated” LL37 acts as better T-cell-stimulator, it loses DNA-binding ability and the associated “adjuvant-like” properties. Since LL37 undergoes a further irreversible post-translational modification, carbamylation and antibodies to carbamylated self-proteins other than LL37 are present in SLE, here we addressed the involvement of carbamylated-LL37 in autoimmunity and inflammation in SLE. We detected carbamylated-LL37 in SLE-affected tissues. Most importantly, carbamylated-LL37-specific antibodies and CD4 T-cells circulate in SLE and both correlate with disease activity. In contrast to “fully citrullinated-LL37,” “fully carbamylated-LL37” maintains both innate and adaptive immune-cells’ stimulatory abilities: in complex with DNA, carbamylated-LL37 stimulates plasmacytoid dendritic cell IFN-α production and B-cell maturation into plasma cells. Thus, we report a further example of how different post-translational modifications of a self-antigen exert complementary effects that sustain autoimmunity and inflammation, respectively. These data also show that T/B-cell responses to carbamylated-LL37 represent novel SLE disease biomarkers.     

矿物质催化合成SP及SP-C

探索出一种以矿物质（橡胶填充剂）为催化剂合成ＳＰ及ＳＰ－Ｃ的新工艺。选择了最佳的工艺条件。此法制成的ＳＰ及ＳＰ－Ｃ产品性能优良、质量稳定。     

成品催化剂间歇控制系统设计和实现

以某石化公司新建的一条通用催化剂生产线为背景,介绍间歇过程设计需要遵守的SP88标准和此间歇控制系统的软硬件配置.深入分析TPB(Total Plant Batch)软件功能体系,给出能完成多种成品催化剂制备要求的一个间歇过程控制系统设计和实现方法,并在实际中得到了成功应用.     

Persistence of nonprotein seed amino acid s-(β-carboxyethyl)-cysteine in young leaves ofCalliandra rubescens Ecological implications

The insecticidal nonprotein amino acid S-(-carboxyethyl)-cysteine (S-CEC) is the major free amino acid in the seeds of severalCalliandra spp. where it accounts for up to 2.9 % of dry weight. Lesser amounts of other related S-containing amino acids and an array of nonprotein imino acids derived from pipecolic acid are other constituents. High concentrations of imino acids, which also show insecticidal activity, are maintained in the mature leaves, but sulfur compounds are lacking. In this study the disappearance of S-CEC from the germinating seeds and young seedlings ofC. rubescens was monitored over time. After 10 weeks, S-CEC continues to be found in high concentrations in the stems and new leaves. As young leaves mature, sulfur compounds quickly decrease in concentration. Traces of S-CEC are found in new leaves of plants up to nine months after germination. Whether high concentration of S-CEC in young leaves is due to transportation from the seed or de novo synthesis is unclear. The ecological implications are discussed.     

Interaction of a High‐Velocity Steel Projectile with a High‐Porous Copper–Duralumin Two‐Layer Bumper

The impact of a steel sphere 2 mm in diameter flying with a velocity of 2–7.3 km/sec on a twolayer bumper is considered. The first layer of the bumper is made of finely disperse copper powder with a density of 2.8 g/cm³, and the second layer is made of Duralumin. For identical impact velocities of 3–5 km/sec and identical thicknesses and areal densities of the bumpers, the twolayer bumper leads to better failure of the steel projectile than the Duralumin bumper. In the case of the twolayer bumper used, the maximum penetration depth of fragments into the witness plate and the number of the largest craters are smaller. The order of the bumper layers does not exert any noticeable effect on projectile failure. With the impact velocity increased to 7 km/sec, the difference in shielding properties of the bumpers almost vanishes.